Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.44 (AGT)
 770 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hereditary elliptocytosis (HE) Sp alpha I/74 is a disorder associated with defective spectrin (Sp) heterodimer self-association and an abnormal tryptic cleavage of the 80-kD alpha I domain of Sp resulting in increased amounts of a 74-kD peptide. The molecular basis of this disorder is heterogeneous and mutations in codons 28, 46, 48, and 49 (codons 22, 40, 42, and 43 in the previous nomenclature which did not include the six NH2-terminal amino acids) have been reported. In this study we present data on seven unrelated HE Sp alpha I/74 kindred from diverse racial backgrounds in whom we identified four different mutations all occurring in exon 2 of alpha Sp at codon 28. Utilizing the polymerase chain reaction we established a CGT----CTT; Arg----Leu 28 mutation in one kindred of Arab/Druze origin. In two unrelated white kindred of English/European origin the substitution is CGT----AGT; Arg----Ser 28 and in two apparently unrelated white kindred from New Zealand, the mutation is CGT----TGT; Arg----Cys 28. Finally, in one American black kindred and in a black kindred from Ghana the mutation involves CGT----CAT; Arg----His 28. Allele specific oligonucleotide hybridization confirmed that the probands are heterozygous for the respective mutant alleles. All four point mutations abolished an Aha II restriction enzyme site which allowed verification of linkage of the mutation with HE Sp alpha I/74. Our results imply that codon 28 of alpha Sp is a "hot spot" for mutations and also indicate that Arg 28 is critical for the conformational stability and functional self association of Sp heterodimers.
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PMID:Four different mutations in codon 28 of alpha spectrin are associated with structurally and functionally abnormal spectrin alpha I/74 in hereditary elliptocytosis. 167 39

Hereditary pyropoikilocytosis (HPP) and hereditary elliptocytosis are closely related, congenital disorders of the red blood cell usually associated with defective spectrin self-association and abnormal limited tryptic digestion of the N-terminal of domain of spectrin. Enhanced cleavage by trypsin of spectrin from affected individuals at arginyl residue 45* and lysyl residue 48* frequently yields increased amounts of an alpha 1/74-Kd fragment at the expense of the normal alpha 1/80-Kd parent fragment. Limited tryptic digestion of three unrelated individuals with HPP showed the alpha 1/74 defect. To ascertain the molecular defect responsible for the abnormality, the structure of exon 2 of the alpha-spectrin gene was examined. Genomic DNA from the subjects was amplified by the polymerase chain reaction using primers flanking exon 2. Restriction endonuclease digestion of amplified products showed the loss of the HindIII site at codons 47 and 48 in one allele of subject 1 and abolished the AhaII site at codons 27 and 28 in one allele of subjects 2 and 3. Nucleotide sequence analysis of subcloned amplified DNA from the HPP subjects showed three novel amino acid substitutions. In subject 1 (a black individual), a single base substitution (AAG----AGG) at codon position 48 changes amino acid residue lysine to arginine. In subject 2 (a white individual), a single base substitution (CGT----AGT) at codon 28 changes arginine to serine. In subject 3 (a black individual), a different base substitution at position 28 (CGT----CTT) changes arginine to leucine. These mutations occur at positions of the alpha l domain where other mutations have also been described, indicating that the normal residues at these positions play an important role in spectrin dimer self-association and thus, in membrane stability.
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PMID:Heterogeneity of the molecular basis of hereditary pyropoikilocytosis and hereditary elliptocytosis associated with increased levels of the spectrin alpha I/74-kilodalton tryptic peptide. 187 97

Serological activity of swine IgM and IgG against Brucella abortus in RBPT was determined in relation to four other reactions used in Poland for diagnosing brucellosis standard agglutination test, complement fixation test, antiglobulin test, 2-mercaptoethanol test). Isolation of IgG was performed by the method of filtration on Sephadex gel G-200 of swine sera raised against Brucella abortus S19 by double immunization with suspension of killed bacteria. The presence of a certain Ig class in the fractions thus obtained was confirmed by immunoelectrophoresis and immunodiffusion tests. RBPT revealed the reaction of antibodies of IgM and IgG class which proves usability of this reaction diagnosis both early (IgM) and chronic (IgG) infection with brucellosis. Both classes of antibodies mentioned above were active also in SAT and CTT. Also the results obtained in AGT and MET were found interesting. In one of the sera, the absence of incomplete antibodies was observed, whereas positive reaction in antiglobulin test was found in its fractions containing IgG. This phenomenon was determined as concealment of incomplete agglutinins through higher level of complete antibodies in normal serum. In swine (the results were different from those obtained for cattle), apart from incomplete antibodies in IgG class, the presence of these agglutinins in IgM class was noted. On the other hand, the results obtained in MET proved that IgM antibodies of swine were not totally reduced when affected by 2-mercaptoethanol.
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PMID:[Activity of porcine anti-Brucella abortus immunoglobulins in the acid plate agglutination test (APAT)]. 313 34

McrBC is a GTP-dependent restriction endonuclease of E. coli K12, selectively directed against DNA containing modified cytosine residues. McrB, one of its components, is responsible for the binding and, together with McrC, for the cleavage of DNAs containing two 5'-Pu(m)C sites separated by 40-80 base pairs. Gel retardation assays with wild-type and mutant McrB reveal that (i) single 5'-Pu(m)C sites in DNA can be sufficient to elicite binding by McrB. Binding to such substrates is, however, weak and strongly dependent on the sequence context of Pu(m)C sites. (ii) Strong DNA binding (K(ass) approximately 10(7)M[-1]) is dependent on the presence of at least two Pu(m)C sites, even if they are separated by less than 40 bp, and is modulated by the sequence context (-A(m)CCGGT- --> -A(m)CT(C/G)AGT- --> -AGG(m)CCT- --> -AAG(m)CTT-). (iii) DNA binding by McrB is accompanied by formation of distinct multiple complexes whose distribution is modulated by GTP. (iv) McrC, which cannot bind DNA by itself, moderately stimulates the DNA binding of McrB and converts McrB-DNA complexes to large aggregates. (v) Deletion of the C-terminal half of McrB, which harbors the three consensus sequences characteristic for guanine nucleotide binding proteins, leads to protein inactive in GTP binding and/or hydrolysis and in McrC-assisted DNA cleavage; the protein, however, remains fully competent in DNA binding. (vi) Mutations in McrB which lead to a reduction in GTP binding and/or hydrolysis can affect DNA binding, suggesting that the two activities are coupled in the full-length protein.
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PMID:The recognition of methylated DNA by the GTP-dependent restriction endonuclease McrBC resides in the N-terminal domain of McrB. 934 6

O6-Alkylguanine-DNA alkyltransferase (AGT, EC 2.1.1.63) is a principle DNA repair protein in repairing O6-alkylguanine in DNA, a major premutagenic lesion produced by environmental and therapeutic alkylating agents. AGT plays a critical role in protecting cells against mutation and cytotoxicity induced by these alkylating agents. The existence of a large interindividual variation in human AGT activity level has been observed and we hypothesize that genetic polymorphism of AGT could be an important determinant for this variation. The present study reports the identification of a novel missense polymorphism in the human AGT gene. The polymorphic alteration occurs at codon 143 in exon 5, converting isoleucine (ATC) to valine (GTC). Because Ile143 is adjacent to the alkyl acceptor Cys145 of the AGT active site and is conserved among mammalian AGTs, amino acid substitution at this position may affect the function of AGT. The codon 143 polymorphism appears to be linked to another new polymorphic alteration at codon 178, which converts lysine (AAG) to arginine (AGG). Because it has been reported that human AGT can be truncated at position 176 without loss of activity, the codon 178 polymorphism may not affect AGT activity. The codon 143/178 polymorphism was found in two of 90 (2%) esophageal cancer patients residing in a high incidence area of China, but was not detected in 60 normal individuals residing in the same area. Six of 28 (210%) non-cancer Caucasian individuals, however, were found to carry this polymorphic allele, suggesting a significant ethnic difference in distribution of this codon 143/178 polymorphism between Chinese and Caucasian individuals. In addition, we confirmed the existence of a codon 84 genetic polymorphism previously identified in a Japanese population, which converts leucine (CTT) to phenylalanine (TTT). The distribution of codon 84 polymorphism was 16%, 20% and 36%, respectively, in the Chinese esophageal cancer patients, Chinese and Caucasian non-cancer individuals. Coexistence of codons 84 and 143/178 polymorphic alterations was found in one Caucasian individual. In all the Chinese (n = 150) and Caucasian (n = 28) samples examined, we were unable to detect a previously reported codon 160 polymorphism (Gly to Arg) which occurred in 10-25% of the Japanese individuals and was shown to affect the reaction of AGT with the drug O6-benzylguanine. The functional significance of the codon 143/178 genetic polymorphism of human AGT and its role in determining an individual's susceptibility to environmental alkylating carcinogens and response to alkylating chemotherapeutic drugs both remain to be studied.
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PMID:Genetic polymorphism of human O6-alkylguanine-DNA alkyltransferase: identification of a missense variation in the active site region. 1020 46

The distribution of different genotypes of Yersinia enterocolitica strains recovered from humans and from healthy pigs was investigated using PCR fingerprinting. The thirty six strains of Y. enterocolitica from humans, thirty five strains from pigs and Y. enterocolitica ATCC 9610 strain were included in this study. The tested strains of Y. enterocolitica belonged to O3 and O9 serogroups. The PCR fingerprinting using EAE5 primer (5' CTT AAT CTC AGT AAT GCT GGC CTT GG) made it possible to form five groups among the tested Y. enterocolitica strains. Two groups were very numerously represented by the tested strains. The thirty of Y. enterocolitica O3 strains from humans (thirty one of tested) and eighteen of Y. enterocolitica O3 strains from pigs (twenty of tested) belonged to one group. This group also included Y. enterocolitica ATCC9610 strain and four Y. enterocolitica O9 strains from pigs. All investigated Y. enterocolitica O9 strains from humans and the majority of Y. enterocolitica O9 strains isolated from pigs created a second, numerous group. The third genotype was created by two strains O9 from pigs, and the remaining two strains, isolated from pigs, belonging to O3 and O9 serogroups showed different binding patterns revealed by gel electrophoresis and created two other genotypes. The tested Y. enterocolitica strains which were isolated from humans formed only two groups but Y. enterocolitica strains isolated from pigs were found in five groups but such as the Y. enterocolitica strains from humans, the majority of strains from pigs were in first and second group. The Y. enterocolitica O3 strains regardless of their origin mostly represented the same PCR fingerprinting profile. The tested Y. enterocolitica O9 strains were more genetically diverse and represented four PCR fingerprinting profiles.
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PMID:The application of PCR fingerprinting to the differentiation of Yersinia enterocolitica strains isolated from humans and pigs. 1509 22

In order to construct a saturated genetic map and facilitate marker-assisted selection (MAS) breeding, it is necessary to enhance the current reservoir of known molecular markers in Gossypium. Microsatellites or simple sequence repeats (SSRs) occur in expressed sequence tags (EST) in plants. Many ESTs are publicly available now and represent a good tool in developing EST-SSRs. From 13,505 ESTs developed from our two cotton fiber/ovule cDNA libraries constructed for Upland cotton, 966 (7.15%) contained one or more SSRs and from them, 489 EST-SSR primer pairs were developed. Among the EST-SSRs, 59.1% are trinucleotides, followed by dinucleotides (30%), tetranucleotides (6.4%), pentanucleotides (1.8%), and hexanucleotides (2.7%). AT/TA (18.4%) is the most frequent repeat, followed by CTT/GAA (5.3%), AG/TC (5.1%), AGA/TCT (4.9%), AGT/TCA (4.5%), and AAG/TTC (4.5%). One hundred and thirty EST-SSR loci were produced from 114 informative EST-SSR primer pairs, which generated polymorphism between our two mapping parents. Of these, 123 were integrated on our allotetraploid cotton genetic map, based on the cross [(TM-1xHai7124)TM-1]. EST-SSR markers were distributed over 20 chromosomes and 6 linkage groups in the map. These EST-SSR markers can be used in genetic mapping, identification of quantitative trait loci (QTLs), and comparative genomics studies of cotton.
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PMID:Characteristics, development and mapping of Gossypium hirsutum derived EST-SSRs in allotetraploid cotton. 1634 84

We investigated the frequency of amantadine-resistant influenza A viruses in Nara Prefecture during four epidemic seasons from 2001-02 to 2004-05. Point mutations within the M2 gene were identified using RT-PCR and DNA sequencing analysis. Five viruses (3.4%) with point mutation were observed from 145 strains analyzed. Three viruses (2.0%) possessed a change at position 31 (AGT-->AAT, Ser to Asn), one virus (0.7%) showed a change at position 26 (CTT-->TTT, Leu to Phe), one virus (0.7%) showed a change at position 27 (GTT-->ATT, Val to Ile), and none showed a change at position 30. All of these changes were the transition type of mutation. These results indicated that the possible circulation of drug-resistant viruses to the community was not supported by the findings obtained during the 2004-05 season in Nara.
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PMID:Frequency of amantadine-resistant influenza A virus isolated from 2001-02 to 2004-05 in Nara Prefecture. 1678 5

This study reports on the detection of additional expressed sequence tags (EST) derived simple sequence repeat (SSR) markers for the oil palm. A large collection of 19243 Elaeis guineensis ESTs were assembled to give 10258 unique sequences, of which 629 ESTs were found to contain 722 SSRs with a variety of motifs. Dinucleotide repeats formed the largest group (45.6%) consisting of 66.9% AG/CT, 21.9% AT/AT, 10.9% AC/GT and 0.3% CG/CG motifs. This was followed by trinucleotide repeats, which is the second most abundant repeat types (34.5%) consisting of AAG/CTT (23.3%), AGG/CCT (13.7%), CCG/CGG (11.2%), AAT/ATT (10.8%), AGC/GCT (10.0%), ACT/AGT (8.8%), ACG/CGT (7.6%), ACC/GGT (7.2%), AAC/GTT (3.6%) and AGT/ACT (3.6%) motifs. Primer pairs were designed for 405 unique EST-SSRs and 15 of these were used to genotype 105 E. guineensis and 30 E. oleifera accessions. Fourteen SSRs were polymorphic in at least one germplasm revealing a total of 101 alleles. The high percentage (78.0%) of alleles found to be specific for either E. guineensis or E. oleifera has increased the power for discriminating the two species. The estimates of genetic differentiation detected by EST-SSRs were compared to those reported previously. The transferability across palm taxa to two Cocos nucifera and six exotic palms is also presented. The polymerase chain reaction (PCR) products of three primer-pairs detected in E. guineensis, E. oleifera, C. nucifera and Jessinia bataua were cloned and sequenced. Sequence alignments showed mutations within the SSR site and the flanking regions. Phenetic analysis based on the sequence data revealed that C. nucifera is closer to oil palm compared to J. bataua; consistent with the taxanomic classification.
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PMID:SSR mining in oil palm EST database: application in oil palm germplasm diversity studies. 2086 64

Dahlia (Dahlia variabilis Hort.) is a significant ornamental plant in New Zealand. Symptoms such as mosaic, ring spots, mottling, and veinal chlorosis, suggestive of a viral infection, are often seen in various dahlia collections. To better understand the incidence of viruses in dahlia in New Zealand, several popularly grown cultivars were evaluated for viruses that are known to infect dahlia. Viruses that were tested included Cucumber mosaic virus (CMV), Dahlia mosaic virus (DMV), Impatiens necrotic spot virus (INSV), Tobacco streak virus (TSV), and Tomato spotted wilt virus (TSWV). At least one symptomatic plant was tested from each of the following cultivars: Akito Dawn, Cincinnati Dancer, Hamari Accord, Hamari Rose, LeBatts Prime, LeVonne Splinter, Riverlea Tropicana, Spartacus, Tartan, Tui Connie, and Wandas Antartica. Except for DMV, initial testing was done by ELISA with commercially available kits for the above viruses. In the case of dahlia mosaic, samples were tested for DMV that was described previously (4) and two additional and distinct caulimoviruses (DMV-D10 and DMV-Holland) that were found to be associated with dahlia (1,2). Primer pairs, ORF6st: ATG GAA GAA ATT AAG GCG T and ORF6end: TTG TCT TCA TCC ATA AAG CAG; DenF1: CAG CAA GAA ACA GGA ATT GA and DenR: TTA CAG TCG AAG CTG CTA AA; and Kapht-F: ATG AGT AAT GCT TCA GCA A and Kapht-R: TGA CCA TGG CTT CTA ACT GT were used for the specific detection of DMV-D10, DMV-Holland, and DMV, respectively (1). None of the samples tested were ELISA positive for CMV, INSV, or TSWV. To verify the TSV infection, TSV-specific primers (5'-GTC CAG ACC ATC CAT CCA AC-3' and 5'-TTG ATT CAC CAG GAA ATC TT-3'), designed based on sequences available in GenBank, were used in reverse transcription (RT)-PCR. For DMV, the diagnostic tests used were electron microscopy and PCR followed by amplicon cloning and sequencing. Electron microscopic observation of leaf-dip preparations showed near isometric virions, approximately 50 to 60 nm in all samples tested. PCR showed that all samples tested were positive for DMV-Holland and DMV-D10. While DMV-Holland is a typical caulimovirus, DMV-D10 was found to exist as an endogenous plant pararetroviral sequence in dahlia (3). One sample each from two cultivars, Spartacus and Tui Connie, were positive for TSV by ELISA, RT-PCR, followed by the sequence analysis of the cloned amplicon. The impact of TSV-infected dahlias as a potential source of inoculum remains to be seen. Our results suggested the prevalence of dahlia mosaic-associated caulimoviruses in several dahlia cultivars and the presence of TSV in New Zealand dahlias. Dahlia mosaic continues to be prevalent in several parts of the world (1), and with the current findings in New Zealand, testing for these viruses should be conducted to ensure virus-free status of the propagating material. References: (1) V. Pahalawatta et al. Plant Dis. 91:1194, 2007. (2) V. Pahalawatta et al. Arch. Virol.153:733, 2008. (3) V. Pahalawatta et al. Virology 376:253, 2008. (4) R. D. Richins and R. J. Shepherd. Virology 124:208, 1983.
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PMID:Dahlia mosaic virus and Tobacco streak virus in Dahlia (Dahlia variabilis) in New Zealand. 3076 5


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